OPERATING INSTRUCTION MANUAL - Cryomagnetics, inc.

1 OPERATING INSTRUCTION MANUAL . FOR THE. MODEL LM-500. CRYOGENIC LIQUID. LEVEL MONITOR. !" #$% &' !" $ #. Web: WARNING! DO NOT ATTEMPT TO OPERATE THIS EQUIPMENT BEFORE YOU. HAVE THOROUGHLY READ THIS INSTRUCTION MANUAL . LM-500 Rev CE. MANUFACTURER'S DECLARATION OF CONFORMITY. According to lSO / IEC Guide 22 and EN45014. Manufacturer's Name: Cryomagnetics, Inc. Manufacturer's Address: 1006 Alvin Weinberg Drive Oak Ridge, TN 37830. Declares. the product Product Name: Liquid Cryogen Level Monitor Model Number: LM-500. Product Options: All Options Conforms to the following Product Specifications: Safety: EN61010-1 (95). EN61326-1 (97). EMC: EN61326-1 (97) Electrical Equipment for Measurement, Control and Lab use EMC Requirements EN61000-4-2 (95) Electrostatic Discharge Immunity Test EN61000-4-3 (96) Radiated Electromagnetic Fields EN61000-4-4 (95) Electrical Fast Transient/Burst EN61000-4-5 (95) Amendment A-Surge Immunity Test EN61000-4-6 (96) Amendment A-Immunity to Conducted Disturbances EN61000-4-11 (94) Voltage Dips, Short Interruptions and Voltage Variations Application of Council Directives: The product complies with the requirements of the Low Voltage Directive 73/23/EEC as amended by 93/68/EEC and the EMC Directive 89/336/EEC as amended by 93/68/EEC.

2 Coffey, President Cryomagnetics, Inc Oak Ridge Tennessee May 27th, 2004. TABLE OF CONTENTS. Introduction .. 1. Factory Calibrations, Installed Options and Certification .. 3. Setup .. 5. Line Voltage and Fuse .. 5. Connecting 6. LHe Sensor Calibration .. 8. LN2 Sensor Calibration .. 9. Factory Calibration .. 10. Factory Calibration of a Liquid Helium 11. Factory Calibration of a Liquid Nitrogen Channel .. 12. Factory Calibration of the Analog Output Option .. 13. Operation and Menus .. 15. Liquid Helium Level Monitor Menu Options .. 16. Mode .. 16. 16. Fill .. 17. Interval .. 17. 17. 17. 18. 18. Liquid Nitrogen Level Monitor Menu Options.

3 19. 19. Fill .. 19. 20. 20. 20. 21. RS-232 Computer Interface .. 21. Computer 22. Analog Output .. 22. Audible Alarm .. 22. Automatic Refill .. 23. Theory of 27. Liquid Helium Level Sensing (Superconductive Filament Probes) .. 27. Liquid Nitrogen Level Sensing (Capacitive Probes) .. 28. LM-500 Circuit 28. Limited Warranty Policy .. 31. Appendix A Computer Interface Command Reference .. 33. Appendix B Line Voltage Controller Module - Option 49. Introduction The LM-500 Liquid Cryogen Level Monitor is the most advanced instrument to monitor cryogenic liquids available today. Its versatile architecture allows configuration to virtually any cryogenic fluid.

4 This includes liquid helium, liquid nitrogen, LNG, and many other cryogenic fluids using an appropriate sensing element. With the 2-Sensor option, the instrument has two independent input channels that are factory configurable to either the same or different liquid types. The unit is compatible with liquid helium level sensors based upon industry standard niobium-titanium superconducting elements. Virtually all liquid helium sensor manufacturers use this technology, so the LM-500 can be used with most existing equipment. Flexible calibration procedures allow the use of two, three, or four wire configured liquid helium sensors. Capacitive sensors are used to monitor liquid nitrogen, LNG, and other cryogenic fluids.

5 As with liquid helium sensors, the LM-500 can monitor many manufacturer's capacitive sensors due to advanced circuit design. The LM-500 has user-adjustable high and low setpoints that may be used to control automated refill cycles. With the 2-Sensor option, independent setpoints can be adjusted for each channel. This allows simultaneous control of two liquid cryogen systems with a single LM-500. Also included is a fully adjustable audible alarm. Most commonly set below the low setpoint, the audible alarm can be used to alert the user to a problem with the refill cycle. A separate audible alarm setpoint is included with the 2-Sensor option. Unique features of the LM-500 include a sensor deicing cycle and filament burnout protection for liquid helium systems.

6 This insures reliable, accurate level readings even under the most adverse cryogenic conditions. Computer control via RS-232 is available in the standard configuration. Remote control via the latest command set is available as an option. LabVIEW virtual instrument drivers are available to allow computer control via a familiar, intuitive interface. A wide variety of other options are also available that allow the instrument to be upgraded and tailored to your particular requirements. Cryomagnetics Model LM-500 OPERATING INSTRUCTION MANUAL 1. This Page Intentionally Left Blank Cryomagnetics Model LM-500 OPERATING INSTRUCTION MANUAL 2. Factory Calibrations, Installed Options and Certification LM-500 Serial Number: Input Voltage: 100 VAC: 115 VAC: 230 VAC: Input Channel 1: Type: LHe LN2 Other: Calibration: Sensor Manufacturer / Serial No: Sensor Length: Characteristic Resistance/Voltage: Lead Resistance: Control Output: TTL: Open Collector: _____ Other: _____.

7 Input Channel 2 (Option 3): Not Installed: Type: LHe LN2 Other: Calibration: Sensor Manufacturer / Serial No: Sensor Length: Characteristic Resistance/Voltage: Lead Resistance: Control Output: TTL: Open Collector: _____ Other: Analog Output (Option 1): Not Installed: Type: 0-1 Volt: 4-20mA: Computer Interface Installed: RS-232: X (Option 2): Notes: Certified: Date: Cryomagnetics Model LM-500 OPERATING INSTRUCTION MANUAL 3. This Page Intentionally Left Blank Cryomagnetics Model LM-500 OPERATING INSTRUCTION MANUAL 4. Setup The LM-500 is delivered to you fully tested and ready to operate. This includes sensor calibration if Cryomagnetics supplied the sensor(s) with the instrument.

8 Calibration will also be complete if the active sensing length of an existing sensor(s) was specified at the time of order. Line Voltage and Fuse Unless otherwise specified, the LM-500 is configured for operation using 115 VAC +/- 10%, 50/60. Hz input power. The serial number tag on the rear panel of the unit indicates the factory voltage setting. The line voltage setting can be changed to 100 or 230 VAC if desired. Always disconnect the power cord from the unit prior to opening the case. To open the LM-500, remove the two screws from the rear panel of the unit. Also remove the screws on the RS-232 and Sensor(s)/IO connectors. The rear panel can then be pulled back and the cover of the LM-500 can be slid off.

9 Figure indicates the changes in circuit board jumpers inside the unit used to make a change in line voltage. Figure - Line Voltage Jumper Settings Transformer Primary Jumpers Line Voltage JP1 JP2 JP3 JP4. 100V, 115V Short Open Short Open 200V, 230V Open Short Open Short * For almost all configurations of the LM-500, the gray connection to WP11 is used and the orange lead is not connected. The orange lead is connected to WP11 instead of the gray ONLY if the unit is to be used with 100V/50Hz or 200V/50Hz power AND with liquid helium level sensors having an active sensing length of more than 80 cm. Cryomagnetics Model LM-500 OPERATING INSTRUCTION MANUAL 5.

10 The fuse for the LM-500 is mounted on the main circuit board inside the unit. Should the fuse need to be changed, open the LM-500 as described above. Locate the fuse - it is a cylindrical device labeled F1 and can be found on the right side of the unit near the main transformer. Replace the fuse only with another fuse of the same type. Use only Wickmann part number 19374-035-K (250V, , time lag). Never replace the fuse with a wire. Connecting Sensors Sensors connect to the LM-500 through the rear panel DB-15F connector labeled Sensor(s)/IO . This connector provides service not only to the sensors, but also to the automatic refill signals generated by the LM-500 and the 4-20mA analog output signal.